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Intervals
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<H2 CLASS="section"><A NAME="htoc9">1.4</A>&nbsp;&nbsp;Intervals</H2>
Besides finite domains, ECL<SUP><I>i</I></SUP>PS<SUP><I>e</I></SUP>  also offers continuous domains in the
form of numeric intervals.
These are also implemented by the <EM>ic</EM> library, which is an integration
of an 
integer finite domain solver and interval reasoning over continuous
intervals<SUP><A NAME="text4" HREF="libman002.html#note4">4</A></SUP>.
It solves equations and inequations between 
general arithmetic expressions over continuous or integral variables.
The expressions can include non-linear functions such as <I>sin</I>, built-in
constants such as <I>pi</I>. Piecewise linear unary functions are also available.<BR>
<BR>
In addition to constraints, <EM>ic</EM> offers search techniques 
(<EM>splitting</EM> [<A HREF="libman072.html#VanHentenryck:95"><CITE>20</CITE></A>] and <EM>squashing</EM> 
[<A HREF="libman072.html#lhomme96boosting"><CITE>17</CITE></A>])
for solving problems involving continuous numeric variables.<BR>
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